Canon PowerShot G2 Review

Overall Image Quality

Overall the G2 puts in a very commendable performance.
Metering is improved thanks to the new evaluative metering mode, in a
session of shooting I didn't once have to reach for the exposure compensation
control. Canon have updated the camera's colour processing algorithms
to include the stronger colour and more accurate white balance we've seen
since the IXUS 300 and A20. And resolution is also there, the lens seems
to be more than capable of squeezing a full four megapixels of resolution
out of the sensor.

This camera really loves colour, and especially blue skies
which it seems to draw out almost as though it has a permanent polarizing
filter, rich and deep blue skies seemed to be signature of images taken
with the G2.

Something else the G2's algorithms manage to do is maintain
dynamic range, they seem to deliberately push dark areas up the grayscale
very slightly (to maintain shadow detail) and will do what they can to
maintain the top end without creating a very sharp cut-off at the point
of overexposure. The deliberate ramping of the black point is something
we first saw on the IXUS 300 and it really does help to maintain shadow
detail.

Gone are some of the complaints of last year, but there
are now hints of sharpening / Bayer interpolation artifacts in the way
of jagged diagonals, something some people have noted on EOS-D30 JPEG
files.

Purple Fringing (Chromatic Aberrations)

The G2 suffers a lot less in the way of chromatic aberrations.
In every day shots there's some visible blooming (the overflow of charge
from over exposed pixels to areas of contrast) but there's really nothing
in the way of the strong purple (or magenta) fringes we saw when we tested
the G1. There is some CA but it became apparent that it was far reduced
in 'every day shots'.

Very little visible chromatic aberrations
in an "every day shot"

Our now standard chromatic
aberration test shot

Our standard test shot did show up a very slight fringe and blooming.

Barrel and Pincushion Distortion

As we'd expect (this is the same design and focal length
lens as last year) the G2's lens distortion measured exactly the same
as the G1. There was mild barrel distortion at full wide angle and very
slight (hardly noticeable) pincushion distortion at full tele photo.

Barrel Distortion, 1.1% @ Wide Angle

Pincushion Distortion, 0.5% @ Full
Tele

Jagged (stepped) diagonals

This is an odd artifact which I've only ever seen reported
on EOS-D30 JPEG's. It occurs on diagonal lines which are not quite at
45 degrees, these lines are then 'made up' of groups of pixels in a 45
degree line, stepped one pixel and then repeated. This can be attributed
to either a problem with the Bayer interpolation algorithm or sharpening
algorithm. They exists also in RAW images converted using the supplied
acquire module or RAW file converter. You can clearly see this pattern
in the examples below (magnified 200%).

It's unlikely these artifacts would be visible on a printed page or computer
monitor (and normal viewing sizes) but they are there, and noted.

UPDATE: 17/August/2001

Having gone back through over a thousand sample images shot with the
G2 I'm happy to say that although these artifacts exist in some shots
they're certainly not common to all and can be reduced by shooting with
sharpening set to -1. HOWEVER, then images will need an unsharpen mask
if they're to be used at their native resolution.

The effect can be seen in the 'uneven' width of the vertical lines on
our resolution test chart, in the samples below you can see a comparison
of Normal Sharpening, Low Sharpening and a RAW file acquired as linear
(16-bit, no processing) which has been level adjusted and had a 150% unsharp
mask applied (resaved as JPEG from Photoshop).

JPEG Normal Sharpening

JPEG Low Sharpening

RAW Linear

CONCLUSION: It does to me at least seem to be an effect of (error in?)
Canon's bayer pattern interpolation algorithm which is then being enhanced
by sharpening. Using lower sharpening will help some. The RAW linear did
look the best overall but is impractical for large numbers of images and
it is difficult to return a linear acquired image to its true tone / colour
balance.

COMMENT: Despite some comments made on our discussion forums this newly
added review item is NOT a retraction, if anything it is designed to highlight
this problem and indicate that it does need solving.

White Balance

As mentioned earlier on this page the G2's white balance
presets (Sunny, Cloudy, Incandescent etc.) have all been tweaked and tuned
and performed much better than the G1 (no hue shift, good 'white is white').
Auto white balance didn't fair so well, being only really usable in natural
light. Manual white balance seemed to work well under any type of light.
Note also that Canon has added a new 'Fluorescent H' mode for different
colour tubes.

Outdoors, Auto

Outdoors, Sunny

Outdoors, Cloudy

Outdoors, Manual

Incandescent, Auto

Incandescent, Incan.

Incandescent, Manual

Fluorescent, Auto

Fluorescent, Fluor.

Fluorescent, Fluor. H

Fluorescent, Manual

Dynamic Range

Dynamic range simply defines the range of light the camera
is able to capture before it either loses detail in darkness (shadows
for example) or blows out a highlight (edges of chromed metals are good
examples of this). Most consumer digital cameras only have a 8-bit analog
to digital converters, plus their CCD's are not built to have a particularly
large dynamic range.

Noise is low and dynamic range is high at the lower ISO's,
the G2's clean ISO 50 produces impressive dynamic range results, ISO 100
is also fairly good (though not as good as some), range drops off fairly
significantly at higher sensitivities.

Comments

G2 was my first digital, which produced thousands of excellent pictures.I wanted an SLR again so bought a Rebel T1i in 2010.Later wanted a smaller camera, tried out a Canon SD1200 but poor usability and very poor image quality. I bought a Nikon S6200 which takes very good pictures, but suffers the ills of a small, cheap camera.June 2014 I didn't want to pack my SLR to Europe, so after researching I chose a Powershot G16 over a Fuji X20 and Panasonic ZS40. VERY pleased with the G16!Now to Dec 2014. Bought a Canon EF 24-105 L IS USM for my Rebel. Looks impressive, but after a day taking pictures and comparing results, the G16 is so good, in fact, for outdoors, side by side image quality in many cases is as good or better than the Rebel! Maybe my Rebel is getting tired?IMO, unless photography is your living, the only benefit of a SLR is the picture taking experience (which is significant) and to show off your fancy camera and lenses. Otherwise, a high end compact is sufficient.